A high-frequency leakage current reduction apparatus known as a conventional leakage current reduction apparatus for reducing high-frequency leakage currents that can occur in three-phase power lines laid between an inverter and a three-phase motor, for example, includes a current detection coil for detecting the high-frequency leakage currents, a high frequency amplifier for amplifying the detected high-frequency leakage currents and a matching coil which electromagnetically injects the amplified high-frequency leakage currents into the three-phase power lines in opposite phase (refer to Patent Document 1, for example).